Improvement in atmospheric dental plates



.portant object.

UNITED STATES PATENT OFFICE.

NE'HEMIAH. T. FoLsoM, 0E LAooNIA, 'NEW HAMPsri-rait.`

' IMPROViEMENT INATNIOSPHERIAC DENTAL PLATS'.

Specification forming part of Letters Patent No. 60,871, dated January 1, 1867.

To all whom Aif may concern Be Kit known that I, NEHEMIAH, T. FOL- SOM, of Laconia, in the county of Belknap and State of New Hampshire, have invented a new and useful Improvement in the Atmos# pheric Plates of Articial Teeth; and l do hereby declare that the following is a full and exact description thereof, reference being had to the accompanying drawings, making a part of this specification'- Figure 1 being a top view of the atmospheric plate of an upper set of teeth, the same provided with my improvement; Fig. 2, aperspective view thereof ;-Fig. 3, a section of one edge of the plate.

Like letters designate corresponding parts in all of the figures.

The main difficulty in wearing artificial teeth arises from the imperfection of the means of keeping the air from behind the plates or bases thereof, so that the air ceases to act with pressure on the outside of the plates. Various ways of obviating this difficulty have been devised; `lout none are reliable. surface of theplates are the most common expedient, but not effectual.

I have discovered va very simple and .entirely successful means of effecting this im- It consists in the employment of a slight ridge raised above the. surface of the plate, generally near the edge thereof, the said ridge bearing against the gums or inside surface of the mouth, and serving as a packing-surface to exclude the air with great certainty and efficacy, substantially as-herein set forth.

The ridge is represented by a in the accompanying drawings; and although it may project more or less from the surface of the plate A', yet the amount of project-ion required in most cases is quite little, as shown in Fig. 3, which indicates the full size, and it may vary at different places, soas to adapt it to the uneven surface of the mouth.

In fitti-ng the plate to the mouth there will be found depressions and projections, hard places and soft, iwith greater or less thickness of skin, or other soft tissue over the bones and cartilage around the mouth. Then, to adapt the plate to this unevenness or roughness of surface with my packing-ridge,

Air-chambers or hollows in the backall that is necessary is to pare away the ridge more or less, as the surface may require, and thus the plate is very readily fitted; whereas, with the whole surface of the plate to tit, the operation is very tedious, dicult, and uncertain. Once fitted, since this ridge'is sure to' bear all along against the surface of, and indents itself in, the skin, the atmosphere is i everywhere excluded, and it never fails to retain the plate with certainty.

From the nature and object of this .invention, it will at once be perceived that the ridge most properly should be placed near the edges of the plate, so as to inclose as much of the surface thereof as can conveniently bel done, and such is the arrangement that I usually employ and recommend, substantially as I have indicated in the drawings; but I do not wish to confine myseltto any particular' position, direction, or distance from the edge of the plate.

For similar reasons I also intend to have theridge extend entirely around the plate, and yet I do not intend to limit myself to that, since a ridge going partially around the plate would be useful, and might, in many cases, be sufficient to securely hold the plate. I also contemplate generally only the use of one ridge around each plate; but there may be two or more such ridges, parallel or otherwise, and all or any of them going entirely around the plate, or only partially around.

All such modifications I intend to include and claim in this invention.

This ridge or ridges, wholly or only partially encircling the plate, may be used in connection with atmospheric chambers or hollows in the plate.

The invention is applicable to any kind of material used for the plates or bases of the teeth, whether of gold, vulcanized -india-rubber, or other substance. A

The drawings represent the invention applied to the upper teeth. applicable to the lower teeth.

, The ridge is ordinarily molded and cast with the plate, and may be of about the form and width shown, or may vary therefrom, as desired and found practicable. r

What I claim as my invention, and desire to secure byLetters Patent, is-

1. A packing-ridge applied to the surface of It isalso equally l the atmospheric plates of artificial teeth, sub The above specification of my improvement stautially as and for the purpose herein speeiin thevatmospherie plates of artificial teeth ed. signed by me this 17 th day of May, 1866.

2. This invention Whether as a single' ridge or more, whether7 entirelyI encircling the NEHEMIAH T' EOLSOM' plate or partially only, whether close to the Witnesses: v

ridge or farther from it, and in different diree- J. S. BROWN,

tions, and with any material, as set forth.

HENRY L. FoLsoM. 

